Effects of Hot-Pressing Parameters and Wax Content on the Properties of Fiberboard Made from Paper Mill Sludge


  • Xinglian Geng
  • James Deng
  • S. Y. Zhang


Paper mill sludge, fiberboard, panel density, pressing temperature, pressing time, wax content


Primary sludge combined with 20% secondary sludge was used for the manufacture of fiberboard. A factorial design was carried out to determine the effects of panel density, pressing temperature and time, and wax level on the panel properties of fiberboard. Two levels were employed for each of the four variables, and the panel dimensional stability and mechanical properties were analyzed using Design-Expert software. The statistical analysis indicated that internal bonding (IB) was significantly affected by panel density, pressing temperature, and their interaction. Pressing time and wax level were not directly related to IB. Similarly, modulus of rupture (MOR) was dependent strongly on panel density, pressing temperature, and their interaction, but was not affected by pressing time and wax level. The effect of panel density on modulus of elasticity (MOE) was as strong as on MOR, but the effect of pressing temperature was weaker on MOE than on MOR. MOE was also related to pressing time, but not to wax level. Thickness swelling (TS) was not affected by panel density, but it was significantly dependent on pressing temperature and time. Unexpectedly, wax level did not have significant impact on TS.


ANSI. 2002. Standard A208.2-2002. Medium density fiber-board (MDF) for interior application.nASTM. 1999. Standard D 1037-99. Standard test methods for evaluating properties of wood-base fiber and particle panel materials.nBattaglia, A., N. Calace, E. Nardi, B.M. Petronio, and M. Pietroletti. 2003. Paper mill sludge-soil mixture: Kinetic and thermodynamic tests of cadmium and lead sorption capability. Microchem. J.75:97-102.nBeauchamp, C. J., M.-H. Charest, and A. Gosselin. 2002. Examination of environmental quality of raw and composting de-inking paper sludge. Chemosphere46:887-895.nChow, P., Z. Bao, J.A. Youngquist, G.M. Rowell, J.H. Muehl, and A. M. Krzysik. 1996. Properties of hardboards made from acetylated aspen and southern pine. Wood Fiber Sci.28(2):252-258.nDavis, E., S. M. Shaler, and B. Goodell. 2003. The incorporation of paper deinking sludge into fiberboard. Forest Prod. J.53(11/12):46-54.nGeng, X., S. Y. Zhang, and J. Deng. 2006. Characterization of paper mill sludge and its utilization for the manufacture of medium density fiberboard. Wood Fiber Sci. (accepted).nHenry, C. L. 1991. Nitrogen dynamics of pulp and paper sludge to forest soils. Water Sci Technol.24(3/4):417-425.nLatva-Somppi, B., H. N. Tran, D. Barham, and M. A. Douglas. 1994. Characterization of deinking sludge and its ashed residue. Pulp Paper Can.95(10):31-35.nLavrent'ev, S. P., S. N. Dmitriev, and E. A. Gavrilivi. 1979. Possibility of using activated sludge as a binder in the production of laminated fiberboard tiles. Vodopol'zovanie, Ochistka Stochn. Vod i Utilizatsiya Osadkov, L.: 98-103.nLi, K., and X. Geng. 2005. Formaldehyde-free wood adhesives from decayed wood. Macromol. Rapid Commun.26:529-532.nPridham, N. F., and R. A. Cline. 1988. Paper mill sludge disposal: Completing the ecological cycle. Pulp Paper Can.89(2):70-72.nSuchsland, O., G. E. Woodson, and C. W. Mcmillin. 1987. Effect of cooking conditions on fiber bonding in dry-formed binderless hardboard. Forest Prod. J.37(11/12): 65-69.n






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